JAVA 1.5 enum > typehandler woes

[Raymond McDermott <ra...@mcdermott.be>]

I am having some, ahem, fun trying to get enums persisting as varchars using
iBatis 2.3 for Java

Can I just check something... is there are a 'proper' way for iBATIS to
persist enums or do we really have to write a typehandler?  Is this is
something that the developer group will patch in 2.x or is there something
more fundamental in the architecture that makes it a 3.0 feature?

Also, I wonder if i have to do something extra in the definition of an ENUM
to support access by the typehandler framework?

Anyway, for the moment it seems that we are stuck with the, IMHO overly
complex, task of scripting support for our enum types.  I am getting null
pointers despite debugging the code and seeing that the typehandler is being
properly registered and invoked.

I have a simple enum class 'frequency':

---> ENUM START

/**
 * The frequency over which measurements are made
 */

public enum Frequency {
    DAILY,
    WEEKLY,
    MONTHLY,
    YEARLY
}


---> ENUM END

I used the generic enum typehandler from the FAQ:

---> GENERIC TYPEHANDLER START

import java.sql.SQLException;

import com.ibatis.sqlmap.client.extensions.ParameterSetter;
import com.ibatis.sqlmap.client.extensions.ResultGetter;
import com.ibatis.sqlmap.client.extensions.TypeHandlerCallback;

public abstract class EnumTypeHandler<E extends Enum> implements
TypeHandlerCallback
{
    private Class<E> enumClass_;

    public EnumTypeHandler(Class<E> enumClass)
    {
        enumClass_ = enumClass;
    }

    @SuppressWarnings("unchecked")
    public void setParameter(ParameterSetter setter, Object parameter)
            throws SQLException
    {
        setter.setString(((E) parameter).name());
    }

    public Object getResult(ResultGetter getter) throws SQLException
    {
        return valueOf(getter.getString());
    }

    @SuppressWarnings("unchecked")
    public Object valueOf(String s)
    {
        return Enum.valueOf(enumClass_, s);
    }
}

---> GENERIC TYPEHANDLER END

Then I have the simple implementation as proposed in the FAQ:

---> SPECIFIC TYPEHANDLER START

public class FrequencyTypeHandler extends EnumTypeHandler<Frequency> {

    public FrequencyTypeHandler() {
    super(Frequency.class);
    }

}

---> SPECIFIC TYPEHANDLER END

---> IBATIS CONFIGURATION FILE START

<?xml version="1.0" encoding="UTF-8" ?>

<!DOCTYPE sqlMapConfig
    PUBLIC "-//ibatis.apache.org//DTD SQL Map Config 2.0//EN"
    "http://ibatis.apache.org/dtd/sql-map-config-2.dtd">

<sqlMapConfig>

    <typeHandler     javaType="com.opengrail.circles365.domain.Frequency"
                    jdbcType="VARCHAR"
                    callback="
com.opengrail.circles365.config.ibatis.typehandlers.FrequencyTypeHandler"/>

    <typeHandler     javaType="
com.opengrail.circles365.domain.MeasurementType"
                    jdbcType="VARCHAR"
                    callback="
com.opengrail.circles365.config.ibatis.typehandlers.MeasurementTypeTypeHandler
"/>


    <!-- List the SQL Map XML files. They can be loaded from the
         classpath, as they are here (com.domain.data...) -->

    <sqlMap resource="com/opengrail/circles365/config/iBatis-User.xml"/>
    <sqlMap resource="com/opengrail/circles365/config/iBatis-
MeasurementItem.xml"/>

</sqlMapConfig>

---> IBATIS CONFIGURATION FILE END

---> IBATIS SQLMAP FILE START

<?xml version="1.0" encoding="UTF-8" ?>

<!DOCTYPE sqlMap
    PUBLIC "-//ibatis.apache.org//DTD SQL Map 2.0//EN"
    "http://ibatis.apache.org/dtd/sql-map-2.dtd">

<sqlMap namespace="MeasurementItem">

    <resultMap id="result" class="
com.opengrail.circles365.domain.impl.MeasurementItemImpl">
        <result property="frequency" column="FREQUENCY"/>
        <result property="measurementType" column="MEASUREMENTTYPE"/>
        <result property="name" column="ITEMNAME"/>
        <result property="derived" column="ISDERIVED"/>
    </resultMap>

    <select id="findMeasurementItemsByUserId" resultMap="result">
        select     FREQUENCY, MEASURETYPE, ITEMNAME, ISDERIVED
        from     C365MEASUREMENTITEM MI, C365USER U
        where    U.USERID = #value#
        and        MI.USERID = U.ID
    </select>

    <insert id="createMeasurementItem" parameterClass="
com.opengrail.circles365.domain.MeasurementItem">
        insert
        into C365MEASUREMENTITEM (frequency, measuretype, itemname,
isderived, userid)
            select     #frequency#, #measurementType#, #name#, #derived#,
u.id
            from     c365user u
            where     u.userid = #userId#
    </insert>

</sqlMap>

---> IBATIS SQLMAP FILE END

Unit test trace ON INSERT:

org.springframework.jdbc.UncategorizedSQLException: SqlMapClient operation;
uncategorized SQLException for SQL []; SQL state [null]; error code [0];
--- The error occurred in com/opengrail/circles365/config/iBatis-
MeasurementItem.xml.
--- The error occurred while applying a parameter map.
--- Check the createMeasurementItem-InlineParameterMap.
--- Check the parameter mapping for the 'frequency' property.
--- Cause: java.lang.NullPointerException; nested exception is
com.ibatis.common.jdbc.exception.NestedSQLException:
--- The error occurred in com/opengrail/circles365/config/iBatis-
MeasurementItem.xml.
--- The error occurred while applying a parameter map.
--- Check the createMeasurementItem-InlineParameterMap.
--- Check the parameter mapping for the 'frequency' property.
--- Cause: java.lang.NullPointerException
Caused by: com.ibatis.common.jdbc.exception.NestedSQLException:
--- The error occurred in com/opengrail/circles365/config/iBatis-
MeasurementItem.xml.
--- The error occurred while applying a parameter map.
--- Check the createMeasurementItem-InlineParameterMap.
--- Check the parameter mapping for the 'frequency' property.
--- Cause: java.lang.NullPointerException
    at
com.ibatis.sqlmap.engine.mapping.statement.GeneralStatement.executeUpdate(
GeneralStatement.java:94)
    at com.ibatis.sqlmap.engine.impl.SqlMapExecutorDelegate.update(
SqlMapExecutorDelegate.java:505)
    at com.ibatis.sqlmap.engine.impl.SqlMapSessionImpl.update(
SqlMapSessionImpl.java:90)
    at
org.springframework.orm.ibatis.SqlMapClientTemplate$10.doInSqlMapClient(
SqlMapClientTemplate.java:383)
    at org.springframework.orm.ibatis.SqlMapClientTemplate.execute(
SqlMapClientTemplate.java:193)
    at org.springframework.orm.ibatis.SqlMapClientTemplate.update(
SqlMapClientTemplate.java:381)
    at
com.opengrail.circles365.data.impl.MeasurementItemDaoImpl.createMeasurementItem
(MeasurementItemDaoImpl.java:13)
    at
com.opengrail.circles365.service.impl.MeasurementItemManagementImpl.createMeasurementItem
(MeasurementItemManagementImpl.java:25)
    at
com.opengrail.circles365.tests.ServiceImplementationTests.testGoodMeasurementItem
(ServiceImplementationTests.java:56)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(
NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(
DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:585)
    at junit.framework.TestCase.runTest(TestCase.java:154)
    at junit.framework.TestCase.runBare(TestCase.java:127)
    at org.springframework.test.ConditionalTestCase.runBare(
ConditionalTestCase.java:69)
    at junit.framework.TestResult$1.protect(TestResult.java:106)
    at junit.framework.TestResult.runProtected(TestResult.java:124)
    at junit.framework.TestResult.run(TestResult.java:109)
    at junit.framework.TestCase.run(TestCase.java:118)
    at junit.framework.TestSuite.runTest(TestSuite.java:208)
    at junit.framework.TestSuite.run(TestSuite.java:203)
    at org.eclipse.jdt.internal.junit.runner.junit3.JUnit3TestReference.run(
JUnit3TestReference.java:130)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(
TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(
RemoteTestRunner.java:460)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(
RemoteTestRunner.java:673)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(
RemoteTestRunner.java:386)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(
RemoteTestRunner.java:196)
Caused by: java.lang.NullPointerException
    at
com.ibatis.sqlmap.engine.mapping.parameter.BasicParameterMap.setParameter(
BasicParameterMap.java:165)
    at
com.ibatis.sqlmap.engine.mapping.parameter.BasicParameterMap.setParameters(
BasicParameterMap.java:125)
    at com.ibatis.sqlmap.engine.execution.SqlExecutor.executeUpdate(
SqlExecutor.java:79)
    at
com.ibatis.sqlmap.engine.mapping.statement.GeneralStatement.sqlExecuteUpdate
(GeneralStatement.java:200)
    at
com.ibatis.sqlmap.engine.mapping.statement.GeneralStatement.executeUpdate(
GeneralStatement.java:78)
    ... 27 more

Do any of you folks have any ideas?

Thanks in advance for your support.

Ray